[chittychittybangbang]

definitely get codes, autozone usually does free code scans but I haven't been there in a while

could be bad fuel causing clogged injector , could try diesel purge:

http://www.youtube.com/watch?v=sQKc9zVnNuA

worst case is camshaft wear: http://www.myturbodiesel.com/1000q/m...ace-vw-tdi.htm